QtScript fail to select the right overloaded C++ slot.

If an exported QObject slot is overloaded with :

• The same number of parameter.
• The parameters that differs are pointer to classes that have conversion function declared with qScriptRegisterMetaType

The conversion function is called with a data pointer that may not match the expecteed object and QtScript select the last slot that matches the method name and argument count.

I got the issue with Qt 5.9.4, but I looked into QtScript code in 5.12and it seems to be still buggy.

I attached a rough patch that fix the issue at least for parameters that inehrits QObject.